[gtkmm-documentation] Update custom and treeview_popup examples

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 92ef8a7aad2e5b3b29fd04717eab222408b33a07
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Tue Nov 20 10:03:36 2018 +0100

    Update custom and treeview_popup examples
    
    * examples/book/custom/custom_container/mycontainer.[cc|h]:
    * examples/book/custom/custom_widget/mywidget.[cc|h]: on_size_allocate() now
    takes two ints instead of one Gtk::Allocation.
    * examples/book/treeview/popup/treeview_withpopup.[cc|h]: Replace on_event()
    by a Gtk::GestureMultiPress instance.

 examples/book/custom/custom_container/mycontainer.cc | 20 +++++++++-----------
 examples/book/custom/custom_container/mycontainer.h  |  2 +-
 examples/book/custom/custom_widget/mywidget.cc       |  5 ++---
 examples/book/custom/custom_widget/mywidget.h        |  2 +-
 examples/book/treeview/popup/treeview_withpopup.cc   | 20 +++++++++-----------
 examples/book/treeview/popup/treeview_withpopup.h    |  5 ++---
 6 files changed, 24 insertions(+), 30 deletions(-)
---
diff --git a/examples/book/custom/custom_container/mycontainer.cc 
b/examples/book/custom/custom_container/mycontainer.cc
index 06a8d53..18e8b9a 100644
--- a/examples/book/custom/custom_container/mycontainer.cc
+++ b/examples/book/custom/custom_container/mycontainer.cc
@@ -125,7 +125,7 @@ void MyContainer::measure_vfunc(Gtk::Orientation orientation, int for_size,
   }
 }
 
-void MyContainer::on_size_allocate(const Gtk::Allocation& allocation, int  baseline)
+void MyContainer::on_size_allocate(int width, int height, int  baseline)
 {
   //Do something with the space that we have actually been given:
   //(We will not be given heights or widths less than we have requested, though
@@ -151,32 +151,30 @@ void MyContainer::on_size_allocate(const Gtk::Allocation& allocation, int  basel
   Gtk::Allocation child_allocation_two;
 
   //Place the first child at the top-left:
-  child_allocation_one.set_x( allocation.get_x() );
-  child_allocation_one.set_y( allocation.get_y() );
+  child_allocation_one.set_x(0);
+  child_allocation_one.set_y(0);
 
   //Make it take up the full width available:
-  child_allocation_one.set_width( allocation.get_width() );
+  child_allocation_one.set_width(width);
 
   if (visible_one)
   {
     //Divide the height equally among the visible children.
-    child_allocation_one.set_height(allocation.get_height() / nvis_children);
+    child_allocation_one.set_height(height / nvis_children);
     m_child_one->size_allocate(child_allocation_one, baseline);
   }
   else
     child_allocation_one.set_height(0);
 
   //Place the second child below the first child:
-  child_allocation_two.set_x( allocation.get_x() );
-  child_allocation_two.set_y( allocation.get_y() +
-          child_allocation_one.get_height());
+  child_allocation_two.set_x(0);
+  child_allocation_two.set_y(child_allocation_one.get_height());
 
   //Make it take up the full width available:
-  child_allocation_two.set_width( allocation.get_width() );
+  child_allocation_two.set_width(width);
 
   //Make it take up the remaining height:
-  child_allocation_two.set_height( allocation.get_height() -
-          child_allocation_one.get_height());
+  child_allocation_two.set_height(height - child_allocation_one.get_height());
 
   if (visible_two)
   {
diff --git a/examples/book/custom/custom_container/mycontainer.h 
b/examples/book/custom/custom_container/mycontainer.h
index c21f336..20be76b 100644
--- a/examples/book/custom/custom_container/mycontainer.h
+++ b/examples/book/custom/custom_container/mycontainer.h
@@ -33,7 +33,7 @@ protected:
   Gtk::SizeRequestMode get_request_mode_vfunc() const override;
   void measure_vfunc(Gtk::Orientation orientation, int for_size, int& minimum, int& natural,
     int& minimum_baseline, int& natural_baseline) const override;
-  void on_size_allocate(const Gtk::Allocation& allocation, int baseline) override;
+  void on_size_allocate(int width, int height, int baseline) override;
 
   void forall_vfunc(const ForeachSlot& slot) override;
 
diff --git a/examples/book/custom/custom_widget/mywidget.cc b/examples/book/custom/custom_widget/mywidget.cc
index 64f1582..4b0a5e6 100644
--- a/examples/book/custom/custom_widget/mywidget.cc
+++ b/examples/book/custom/custom_widget/mywidget.cc
@@ -108,7 +108,7 @@ void MyWidget::measure_vfunc(Gtk::Orientation orientation, int /* for_size */,
   natural_baseline = -1;
 }
 
-void MyWidget::on_size_allocate(const Gtk::Allocation& allocation, int /* baseline */)
+void MyWidget::on_size_allocate(int width, int height, int /* baseline */)
 {
   //Do something with the space that we have actually been given:
   //(We will not be given heights or widths less than we have requested, though
@@ -116,8 +116,7 @@ void MyWidget::on_size_allocate(const Gtk::Allocation& allocation, int /* baseli
 
   if(m_refGdkSurface)
   {
-    m_refGdkSurface->move_resize( allocation.get_x(), allocation.get_y(),
-            allocation.get_width(), allocation.get_height() );
+    m_refGdkSurface->move_resize(0, 0, width, height);
   }
 }
 
diff --git a/examples/book/custom/custom_widget/mywidget.h b/examples/book/custom/custom_widget/mywidget.h
index 8601681..c3bb027 100644
--- a/examples/book/custom/custom_widget/mywidget.h
+++ b/examples/book/custom/custom_widget/mywidget.h
@@ -36,7 +36,7 @@ protected:
   Gtk::SizeRequestMode get_request_mode_vfunc() const override;
   void measure_vfunc(Gtk::Orientation orientation, int for_size, int& minimum, int& natural,
     int& minimum_baseline, int& natural_baseline) const override;
-  void on_size_allocate(const Gtk::Allocation& allocation, int baseline) override;
+  void on_size_allocate(int width, int height, int baseline) override;
   void on_map() override;
   void on_unmap() override;
   void on_realize() override;
diff --git a/examples/book/treeview/popup/treeview_withpopup.cc 
b/examples/book/treeview/popup/treeview_withpopup.cc
index fcfd9f7..57191f2 100644
--- a/examples/book/treeview/popup/treeview_withpopup.cc
+++ b/examples/book/treeview/popup/treeview_withpopup.cc
@@ -40,6 +40,13 @@ TreeView_WithPopup::TreeView_WithPopup()
   append_column("ID", m_Columns.m_col_id);
   append_column("Name", m_Columns.m_col_name);
 
+  // Catch button press events:
+  auto refGesture = Gtk::GestureMultiPress::create();
+  refGesture->set_button(GDK_BUTTON_SECONDARY);
+  refGesture->signal_pressed().connect(
+    sigc::mem_fun(*this, &TreeView_WithPopup::on_popup_button_pressed));
+  add_controller(refGesture);
+
   //Fill popup menu:
   auto item = Gtk::make_managed<Gtk::MenuItem>("_Edit", true);
   item->signal_activate().connect(
@@ -63,18 +70,9 @@ TreeView_WithPopup::~TreeView_WithPopup()
 {
 }
 
-bool TreeView_WithPopup::on_event(const Glib::RefPtr<Gdk::Event>& event)
+void TreeView_WithPopup::on_popup_button_pressed(int /* n_press */, double /* x */, double /* y */)
 {
-  //Call base class, to allow normal handling,
-  //such as allowing the row to be selected by the right-click:
-  const bool return_value = TreeView::on_event(event);
-
-  //Then do our custom stuff:
-  if (event->get_event_type() == Gdk::Event::Type::BUTTON_PRESS &&
-      std::static_pointer_cast<Gdk::EventButton>(event)->shall_trigger_context_menu())
-    m_Menu_Popup.popup_at_pointer(event);
-
-  return return_value;
+  m_Menu_Popup.popup_at_pointer();
 }
 
 void TreeView_WithPopup::on_menu_file_popup_generic()
diff --git a/examples/book/treeview/popup/treeview_withpopup.h 
b/examples/book/treeview/popup/treeview_withpopup.h
index 3879098..5d5b057 100644
--- a/examples/book/treeview/popup/treeview_withpopup.h
+++ b/examples/book/treeview/popup/treeview_withpopup.h
@@ -26,9 +26,8 @@ public:
   virtual ~TreeView_WithPopup();
 
 protected:
-  // Override Signal handler:
-  // Alternatively, use signalevent().connect_notify()
-  bool on_event(const Glib::RefPtr<Gdk::Event>& event) override;
+  // Signal handler for showing popup menu:
+  void on_popup_button_pressed(int n_press, double x, double y);
 
   //Signal handler for popup menu items:
   void on_menu_file_popup_generic();